TY  - BOOK
AU  -  Lovell,K.
TI  -  The growth of basic mathematical and scientific concepts in children / 
U1  -  372.7019 
PY  - 1968///
CY  -  London : 
PB  -  University of London Press, 
KW  -  Number concept in children
KW  -  Conservation (Psychology)
N1  -  Includes bibliographical references
ER  -